Nitration of cellulose with a nitrogen oxide



Patented July 11, 1933 UNITED STATES PAT cYRIL J. swam) AND JAMES '1. .EUESS, or nooHEsT-nn, new Yonx, Ass enons r0 EASTMAN KODAKCOMPANY, or noonnsrnnnnw YORK, A cone-cannon or'nnw Y A YORK No Drawing.

NO which may be obtained from the gases used in the preparation of nitric acid The use of oxide of nitrogen does away with the necessity of preparing the nitric acid from the oxide.

The following examples are given as illustrative of our invention with the use of the nitrogen oxide 111 the gaseous and in the 1161- uid state.

Ewa-mple I About 10 grams of cellulose in the form of cotton linters may be flufied so as to insure uniform treatment. WVith some forms of cellulose such ,as cotton dust this procedure is obviously entirely umiecessary and may even be omitted in the present process. The material is then placed in a vacuum desiccator and the air is removed therefrom. Gaseous N0 is then introduced until a concentration of N0 in the vessel is quite high.

The cellulose is allowed to stand in this atmosphere until the desired nitration is obtained. If desired, the gas may be changed at intervals during this treatment or con tinuously passed through" the cellulose. Ni-

tration has been found to take place after 1-2 hours. However, the treatment is preferably continued for 18 hours. The resulting product showed upon analysis a nitrogen content of about 1.38% nitrogen.

Ewample [I About 10 grams of cellulose (cotton linters preferred) are placed in about c. c. of liquid N0 and kept at a temperature of 10 C. After allowing the material to re- NITRATION or onLLuLosn wirnnnnrnosnn oxinn Application filed December 31, 1930. Serial No. 505,965.

main at this temperature for the desired re or T time, the mixture is removed and the N0 may be driven 05 by pouring offthe liquid and boiling the remaining N02 or by blowing it out by air. If desired, the remaining ma terial may be washed in a dilute solution of sodium bicarbonate. The amount, of liquid NO used and the temperature and time may be varied if desired. It has been found that this reaction proceedsvery rapidly at first, but then decreases perceptibly in rate so that with further treatment the nitrogen content increases very slowly. When time is a factor, therefore, a very short time may be used, but if the nitrogen content is the controlling factor the process may be allowed to run 72 hours or even longer, if desired. It was found upon carrying the process out for 48 hours that the nitrogen content of the resulting product was HBO-11.95%. Other containing alpha, beta and gamma cellulose and high grade wood pulps or other like material.

As pointed out previously the time of I treatment of the cellulose with the oxide of nitrogen maybe varied within wide limits,

depending on the nitrogen content desired.

nitrogen as the nitrating agent a temperature below the boiling'pomt of the oxide is desirable, in the treatment. of the cellulose with the gaseous nitrating agent it is even desir- Although in the use of the liquid oxide of able to Warm the gases which pass into the reactionchamber. It is also desirable though not essential that enough gas is passed into What we claim'as our invention and desire the 'chamber'so that the pressure therein bet-.9

to secure by Letters Patent of the United is: I

1. A process of nitrating cellulose which comprises treating the cellulose with a bath NO comprising a nitrating agent substantially consisting of a nitric oxide.

2. A process of nitrating cellulose which comprises treating the cellulose with a higher oxide of nitrogen in gaseous form.

3. A process of nitratin'g cellulose which comprises treating the cellulose with a bath comprising a nitrating agent substantially consisting of aliigher oxide of nitrogen in liquid form. 

